WO2003037477A1

WO2003037477A1 - Backwashable filtration apparatus and method of backwashing filtration apparatus

Info

Publication number: WO2003037477A1
Application number: PCT/JP2002/011387
Authority: WO
Inventors: Atsushi Sakamoto; Hisayuki Kataoka
Original assignee: Pall Corporation
Priority date: 2001-10-31
Filing date: 2002-10-31
Publication date: 2003-05-08
Also published as: JPWO2003037477A1

Abstract

A method of backwashing a filtration apparatus (1), which comprises allowing a compressed gas to backflow from the secondary side (5) of the filtration apparatus (1), to thereby generate bubbles in the fluid to be filtered in the primary side (4) of the filtration apparatus (1) and disperse a material in a gel form and/or viscous material captured by the filter element (3) of the filtration apparatus (1) into the fluid to be filtered in the primary side (4), and then discharging the dispersed material in a gel form and/or viscous material from the filtration apparatus (1) together with the fluid to be filtered in the primary side (4). The method allows the backwash of a filtration medium with a filtration apparatus being installed, which leads to the achievement of filtration of a fluid to be filtered containing a lot of a material in a gel form or viscous material.

Description

Description Filtration apparatus capable of backwashing and backwashing method for filtration apparatus

INDUSTRIAL APPLICABILITY The present invention enables gel filtration and particle filtration, and in particular, has a long filtration life and is capable of backwashing even when filtering a filtration fluid containing a gel or highly viscous substance. And a method for back washing a filtration device. Background art

Conventionally, a laminated pleated filter having a function of removing a gel-like substance from a filtration fluid has been proposed. For example, Japanese Patent Application Laid-Open No. 7-21838 / 14 discloses a pleated particle removing layer having a cylindrical shape as a whole, and a hollow cylindrical gel filtration layer arranged in multiple layers around the particle removing layer. Thus, a laminated pre-filter that performs gel filtration and particle removal is disclosed. Although this laminated pre-filter can be used up to a filtration pressure difference of about 5 kgf / cm ^2, it is a cylindrical type in which a plurality of filtration layers composing a gel filtration layer are concentrically stacked, so that gel The gel penetrates into the filtration layer up to the filtration layer where the water is trapped, or the gel is trapped near the surface of the filtration layer and the filtration layer is closed, so that it is substantially close to one layer. Therefore, other filtration cannot be used effectively. Therefore, the filtration area is not sufficient. For this reason, the total amount of gel-like substances that can be captured by the gel filtration layer must be extremely small as compared with the pleated filtration layer.

On the other hand, a laminated pleated filter disclosed in Japanese Patent Application Laid-Open No. H11-3194427 is an inner-layer pleated filter having the function of a normal filtration filter, and an inner-layer pleated filter. An outer-layer pleated filter which is disposed on one outer peripheral portion and mainly has a function of removing a gel-like substance. Raised or cilia are formed in the valleys of the outer layer of the pleated filter, and the raised or cilia are intended to effectively capture the gel-like substance. This multilayer pleated filter has a pleated shape because the outer layer filter for trapping the gel-like substance is pleated. JP02 / 11387 It is considered that the trapped amount of the gel-like substance is larger than that of the multilayer filter disclosed in Kaihei 7-2 1 3 8 14. However, the maximum Filtration pressure difference that can be used in layered filter 0.3 because it is kgf / cm ^2, 0.3 multiplied by kg ip / cm ² or more filtration differential pressure, a gel-like material to deform the outer layer After passing through the filter, it is trapped by the filter for particle removal arranged in the inner layer, and the inner layer filter is clogged. The filtration life of a filter is expressed as the product of the filtration differential pressure that can be applied to the filter, the filtration area of the filter, and the volume of the substance captured by the filter retained by the filter, the so-called retention capacity. Is done. Therefore, it cannot be said that the filtration life of the laminated pleated fill Yuichi disclosed in Japanese Patent Application Laid-Open No. H11-3194427 is sufficient. There is also a large pleated filter specializing in the capture of gel-like substances.

. The pleated filter has a plurality of filter elements each having a rhombic cross-sectional shape, and has an annular valley between adjacent chevrons for capturing a gel-like substance. This filter is called a candle pre-filter because of its unique overall shape. This candle pleated filter has a large filtration area because of its large size, but requires a large installation space and does not have a particle removal function.

In all of the above-mentioned conventional filter devices, the filter fluid after filtration and the fluid for washing are pressure-fed in the direction opposite to the filtration direction, thereby washing and regenerating the clogged gel filtration filter. So-called backwashing cannot be performed. In particular, in a resist stripping process in a semiconductor manufacturing process, a large amount of resist residue is generated in a fluid as a gel-like foreign substance. When such a filtration fluid is filtered, the reverse of the gel filtration filter is appropriately performed. Without cleaning, the filtration life of the filter will be extremely short. Some filters are configured to replace only one gel filtration filter instead of performing backwashing.However, filter replacement requires a long time and requires frequent filter replacement. For this reason, it was practically extremely difficult to filter highly viscous organic exfoliated substances in production lines such as factories.

The gel filtration filter of the conventional filter device is particularly known as a so-called air-assist bag that uses a pneumatic pressure or the pressure of another compressible fluid to pump a cleaning liquid. When T / JP02 / 11387 washes were used, there was a problem that the gel filtration filter itself was deformed by the pressure of the washing liquid, making it impossible to reuse it. Summary of the Invention

An object of the present invention is to enable filtration of a filtration fluid containing a large amount of a gel-like or highly viscous substance by enabling back-washing of a filtration medium while a filter device is installed. It is to provide a filtration device and a filtration method. Further, an object of the present invention is to apply a pressure to a liquid for back washing by using a secondary-side air vent port for exhausting air mixed in a filtrate after filtration, thereby providing a filter. The present invention provides a filter and a filtration device capable of easily performing regeneration cleaning by air-assisted backwash while suppressing restrictions on the arrangement of the filtration device. And a drain / support layer that does not substantially capture gels or particles, a gel filtration layer that captures gel, and a particle removal layer that captures fine particles are sequentially arranged from the upstream side to the downstream side. It is characterized by. According to the filter having such a configuration, after filtration is performed by pressurizing with a compressed gas such as air pressure from a secondary air vent port or a secondary side filtrate outlet port located downstream of the particle removal layer. When the filtration fluid or washing liquid is pumped toward the gel filtration layer, the gel-like substance adhering to the upstream surface of the gel filtration layer is separated from the gel filtration layer. The introduction of the compressed gas is not particularly limited as long as it is on the secondary side, but it is preferable to introduce the compressed gas from the secondary-side air vent port. It is desirable to introduce from the upper side of the filter. However, it may be introduced from the lower secondary side of the filter. The exfoliated gel-like substance is discharged from a drain port or a primary air vent port disposed on the upstream side of the gel filtration layer, and if the drain port is closed, normal filtration work can be resumed. At the time of back washing of the filter, the pressure of the liquid used for washing is applied to the gel filtration layer from the downstream side to the upstream side, and the gel filtration layer tends to be displaced to the upstream side. Since the external support is disposed, the gel support is prevented from being displaced by the external support. Further, a drain / support layer is disposed upstream of the gel filtration layer, and the drain / support layer supports the adjacent filters of the gel filtration layer so as not to overlap with each other. Gel filtration layer pre As a result, the same shape as before the back washing can be maintained. Therefore, after back washing, the filter returns to the initial state, and the intended filtration performance is restored.

Further, the backwashable filtration device of the present invention comprises a backwashable gel filtration filter having a drainage Z support layer that does not substantially capture gels or particles, and a gel filtration layer that captures gel. And a filter for removing particles, which is disposed on the downstream side of the filter for gel filtration and has a particle removing layer for capturing fine particles. This filtration device is characterized in that the gel filter and the filter for particle removal are configured as separate units, and only the gel filtration layer, which is likely to cause clogging at an early stage, can be back-washed. However, an air vent port communicating with the filter housing is provided at the upper part of the filter element for gel filtration and on the secondary side of the filter element for particle removal filter, respectively. By supplying a compressed fluid from the air vent port for pumping the gel, back washing of the gel filtration layer and back washing of the particle removal layer can be performed at the same time.

Further, in the backwashing method of the present invention, the compressed gas is caused to flow backward from the secondary side to the primary side of the filtration device, thereby generating bubbles in the filtration fluid on the primary side, thereby using the gel for filtration. The gel substance trapped in the filter is dispersed in the primary filtration fluid, and then the gel substance dispersed in the filtration fluid is discharged from the filtration device together with the primary filtration fluid.

It should be noted that if at least the drainage Z support layer, the gel filtration layer, the particle removal layer, and the other liquid contact parts among the constituent elements of the filtration device of the present invention are made of an organic material, they will be intense as in a semiconductor manufacturing device. Equipment that uses corrosive chemicals improves corrosion resistance and extends filtration life. In particular, it is preferable to use a fluorine-based resin—a polyethylene resin—excellent in chemical resistance, heat resistance, and low extractability of Pt class.

In order to regenerate the filter element by effectively removing the gel-like substance at the time of back washing of the filtration device of the present invention, an air vent port is provided on each of the primary side and the secondary side of the filtration device. A drain port is provided in the filter, and when the filtration device is backwashed, after opening the air vent port on the primary side, compressed gas is introduced from the air vent port on the secondary side to generate air bubbles in the filtered fluid, which results in gel filtration Gel captured by a filter The substance is dispersed in the primary filtration fluid. Next, the drain port is opened, and the gel-like substance dispersed in the filtration fluid is discharged together with the filtration fluid on the primary side. The gel-like substance captured by the filtration device is separated from the filter element by the collision of a large number of bubbles generated in the primary-side filtration fluid. The introduction of the compressed gas is preferably provided at the air vent port, but may be introduced from the filtrate outlet port side. Prior to the regeneration cleaning by the air-assisted backwash, the undiluted solution supply valve and the return solution are used. After closing the outlet valve, drain discharge valve, primary-side air release valve, secondary-side air release valve, and air-assist backwash valve, and opening the air-assist backwash valve located on the secondary side, the primary side By opening the air release valve, the viscous gel is separated from the gel filtration layer while generating a large amount of air bubbles in the primary chamber of the housing, and the viscous gel is dissolved by performing a bubbling operation with sufficient stirring. After the above-mentioned valves are closed, the air-assisted backwash valve is opened and the drain discharge valve is opened before the dispersed gels aggregate again. By releasing the gel, the separated gel can be regenerated without re-adhering to the gel filtration layer. As a result, it is possible to regenerate and wash the backwash solution required for backwashing without providing a separate storage tank, so that waste liquids can be minimized.Thus, the economic burden and the environmental burden due to the discharge of valuable and toxic liquids are greatly reduced. it can. Of course, if necessary, it is more preferable to provide a separate storage tank for the back-washing liquid so that more complete regeneration cleaning can be performed. Whether or not to do so may be appropriately selected in consideration of the optimal conditions of the production process and equipment such as the properties of the gel, economic burden and environmental load.

Further, in the filtration apparatus of the present invention, the drainage / support layers formed of a mesh material 8 0 0 _m or less in thickness in 2 0 0 or more, the average pore size of 2 5 0 m hereinafter gel filtration layer with one or more The particle removal layer can be set to have a filtration accuracy of microfiltration or ultrafiltration.

In the filtration device of the present invention, the maximum operating pressure difference during filtration can be set to 1.0 kgί / cm ^2, and the pressure during back washing can be set to 2.0 kgf / cm ² or less. By properly setting the bubble generation conditions, the backwash pressure at the time of drain discharge is lower than the backwash pressure at the time of bubble generation as long as the primary room liquid after the bubble generation can be quickly discharged. It is possible to reduce the time required for backwashing strips. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a half sectional view of an embodiment of the filtration device of the present invention.

FIG. 2 is a piping diagram of the filtration device of the present invention.

FIG. 3 is a piping diagram showing another piping example of the filtration device of the present invention.

FIG. 4 is a view showing an experimental result of the filtration device of the present invention.

FIG. 5 is a cross-sectional view of one embodiment of the filter element of the filtration device of the present invention.

FIG. 6 is a cross-sectional view of another embodiment of the filter element of the filtration device of the present invention.

FIG. 7 is a perspective view of the filter element of FIG.

FIG. 8 is a conceptual diagram of another embodiment of the filtration device of the present invention. Detailed description of the invention

Hereinafter, embodiments of the present invention will be described with reference to the drawings and experimental examples.

As shown in FIG. 1, the filtration device 1 of the present invention is configured by housing a filter element 3 in a filter housing 2. A primary chamber 4 is formed between the filter housing 2 and the filter element 3, and a secondary chamber 5 is formed in the center of the filter element 3. In the upper part of the filter housing 2, a primary communication chamber 6 communicating with the primary chamber 4 and a secondary communication chamber 7 communicating with the secondary chamber 5 are formed. Similarly, at the lower portion of the filter housing 2, a primary communication chamber 8 communicating with the primary chamber 4 and a secondary communication chamber 9 communicating with the secondary chamber 5 are formed. I have.

The primary communication chamber 6 formed in the upper part of the filter housing 2 communicates with the inflow port 10 for the filtrate (stock solution) and the primary air vent port 11 and communicates with the secondary communication chamber. 7, the outlet port 12 for the filtrate after filtration and the air vent port 13 on the secondary side communicate with each other. A drain port 14 for discharging waste liquid on the primary side communicates with a communication chamber 8 on the primary side formed at a lower portion of the filter housing 2, and a communication chamber 9 on the secondary side has Drain port 15 for discharging waste liquid on the secondary side communicates.

After closing the air vent ports 11 and 13 and closing the drain ports 14 and 15, the filtrate (stock solution) flowing in the A direction from the inflow port 10 flows to the primary Through the communication chamber 6 on the side, the chamber 4 on the primary side, the filling element 3, the chamber 5 on the secondary side, and the communication chamber 7 on the secondary side, flow in the direction of the arrow in Figure 1, and from the outflow port 12 Outflow in B direction.

The filtration device 1 can be used with the communication chambers 6 and 7 arranged above as shown in Fig. 1, but it can also be used with the communication rooms 6 and 7 arranged upside down in the state shown in Fig. 1. Wear. When placed upside down from the state in Fig. 1, the primary air vent port 11 functions as the primary drain port, and the secondary air vent port 13 acts as the secondary drain port. Function. At this time, the drain port 14 on the primary side functions as an air vent port on the primary side, and the drain port 15 on the secondary side functions as an air vent port on the secondary side. In each case, the filtrate (stock solution) flows into the filter housing 2 from the inflow port 10, and the filtrate after filtration flows out of the filter port 18 from the outflow port 12. I do.

FIG. 2 is a piping diagram when the filtering device 1 is used in the arrangement of FIG. 1, and FIG. 3 is a piping diagram when the wind filtering device 1 is arranged upside down from the arrangement of FIG.

In Fig. 2, during normal filtration, valves V1, V2, and V4 are opened, valves V3 and V5 are closed, and filtrate (filtrate tank) 16 The undiluted solution) is fed to the inflow port 10 and the filtrate after filtration is taken out from the outflow port 12. If the filter element 3 in the filter device 1 is clogged by such a filtering operation, the filter element 3 is backwashed. For backwashing of filter element 3, open valves V4 and V3, close valves VI, V2 and V5, and pressurized gas (normally compressed air) from outlet port 13 on the secondary side. To the chamber 5 on the secondary side, and the pressure of the compressed fluid causes the filtrate in the chamber 5 on the secondary side to flow back through the filter element 3 into the chamber 4 on the primary side. This is done by generating a large number of bubbles in the chamber 4 of the chamber. As a result, the primary room The gel-like or highly viscous substance (not shown) trapped in the filter element 3 is separated from the filter element 3 and separated into the primary chamber 4 and the primary chamber 4. It diffuses into the filtrate in the communication chamber 6. At this time, the valves V3 and V5 are opened, the valves VI, V2 and V4 are closed, and the filtrate in the primary side chamber 4 and the primary side communication chamber 6 is connected from the primary side drain port 14. Eliminate the gel-like or highly viscous substances mixed into this. When draining is complete, open valves VI, V2, V4, close pulp V3, V5 and start normal filtration. In the case of Fig. 3, during normal filtration, the valves VI, V2, V4, are opened, the valves V3, V5 are closed, and the filtrate (stock solution) in the filtrate tank (stock solution tank) 16 flows in. It is fed to port 10 and the filtrate after filtration is taken out from outlet port 12. If the filter element 3 in the filtration device 1 is clogged by such a filtering operation, the filter element 3 is back-washed. To backwash the filter element 3, open the valves V4 and V3, close the valves VI, V2 and V5, and discharge compressed gas (usually compressed air) from the air vent port 13 on the secondary side. It is supplied to the secondary chamber 5, and the pressure of the compressed fluid causes the filtrate in the secondary chamber 5 to flow back through the filter element 3 into the primary chamber 4, and This is done by generating a large number of bubbles in the chamber 4 of the chamber. As a result, the gel-like or highly viscous substance (not shown) trapped in the filter element 3 is separated from the filter element 3 in the primary side chamber 4. It diffuses into the filtrate in the chamber 4 on the primary side and the communication chamber 6 on the primary side. At this time, the valves V3 and V5 are opened, the valves VI, V2 and V4 are closed, and the filtrate in the primary side drain port 14 and the primary side chamber 4 and the primary side communication chamber 6 And the gel-like or highly viscous substance mixed into it. When draining is complete, open valves VI, V2, V4, close valves V3, V5 and start normal filtration. Fig. 4 shows the test results when the filter 1 was arranged as shown in Fig. 2 and the organic stripper washes back (backwash) under the following test conditions.

(1) Test method

a. Test housing

Inner diameter: Φ 97.5 mm In, Out: 3/4 inch

Ve n t, D r a i n: 3/8 i n c h

A i r I n l e t: 3/8 i n c h

b. Test filter: filtration accuracy 50 ^ m, effective filtration area 0.10 m ²

c. Test liquid: IPA-dispersed pseudo-organic stripping contaminant: Re-dispersed filter-collected contaminants from filter used in organic stripping process

d. Flow condition: Air pressurization with constant primary pressure 0.07 kg fZcm ²

. e Bakkuwosshu Condition: the filter one secondary vent port, air introduced by the valve opening and closing: pipe diameter 3Z8 inc, pipe length 2m, pressure 0. 2 kgf / cm ^2, pressing time 1 minute

f. Challenge: I PA Dispersion filter-recovery contamination

Test pressure: 1 Ps i

h. Backwash air: 0.5 kg iZcm ²

(2) Result

Test Filter one as filtration accuracy 50, using the effective filtration area of 0. 1 0 m ² filter, was passed through a pseudo organic stripping contaminants solution of I PA dispersion, when passing fluid 6 rate Torr flow rate early It became 1Z6 and clogged. After that, a backwash was performed by introducing air from the secondary side at the festival. The pseudo organic stripping contaminant solution was passed through the filter again, and the change in the flow rate was monitored. As a result, the flow rate immediately after the backwash was the same as that when the liquid was passed through for the first time. The test cycle was repeated eight times thereafter. As a result, the initial flow velocity was recovered immediately after the pushback (see Figure 4).

FIG. 5 is a transverse sectional view of the filter element 3. Inside the outer support 17, a drainage Z support layer 18 that does not substantially capture gels or particles, a gel filtration layer 19 that captures gel, and a particle removal layer 20 that captures fine particles are on the upstream side. From the downstream to the downstream side. 21 and 22 are cylindrical support members. The drainage / support layer 18 and the gel filtration layer 19 have a so-called ordinary pleated form, and the particle removal layer 20 has a lay-over-barrier form.

6 and 7 show another embodiment of the filter element 3 and the filter body 3 JP02 / 11387a includes a drain / support layer 18 that does not substantially capture gel or particles, a gel filtration layer 19 that captures gel, a particle removal layer 20 that captures fine particles, and another wastewater Z. The support layer 23 is arranged from the upstream side to the downstream side.

As shown in FIG. 8, the filter device of the present invention comprises a filter housing 24 containing a gel filtration layer 19 for capturing gel, and a filter housing containing a particle removal layer 20 for capturing fine particles. It is also applicable when 25 is configured separately.

As described above, according to the present invention, the filter medium can be back-washed while the filter device is installed, so that a large amount of a gel-like or highly viscous substance is contained. A filtration device and a filtration method capable of filtering a filtration fluid can be provided.

Claims

The scope of the claims

1. An external support, a drainage Z support layer that does not substantially capture gels or particles, a gel filtration layer that captures gels, and a particle removal layer that captures fine particles are arranged from upstream to downstream from the upstream side. A filtration device capable of backwashing, which is sequentially arranged.

2. The filter according to claim 1, wherein an air vent communicating with a filter housing of the filter is provided at an upper portion of a secondary side of a filter element of the filter.

3. The filtering device according to claim 1 or 2, wherein at least the drainage / support layer, the gel filtration layer, the particulate removal layer, and other liquid contact parts are made of an organic material. .

4. The filtration device according to claim 1, 2, or 3, wherein an air vent port is provided on each of a primary side and a secondary side of the filtration device, and a drain port is provided in the filtration device, and the filtration device is used for backwashing. After opening the air vent port on the primary side, compressed gas is introduced from the air vent port on the secondary side or the secondary side to generate air bubbles in the filtration fluid, whereby the gel filtration is performed. The filter device, wherein the gel substance trapped by the filter for water is dispersed in the filtration fluid on the primary side, and then the dispersed gel substance is discharged from the drain port.

5. The filtration device according to any one of claims 1 to 4, wherein the drainage / support layer is made of a mesh material having a thickness of 200 m or more and 800 xm or less, The gel filtration layer has an average pore size of 1 m or more and 250 m or less, and the particle removal layer is set so as to have filtration accuracy of microfiltration or ultrafiltration.

6. In the filtration device according to any one of claims 1 to 5, the maximum differential pressure operation at the time of filtration 1. And 0 kgf / cm ^2, the pressure during backflushing 2. 0 kgf / cm ² or less, wherein the filtration device.

7. The filtering device according to any one of claims 1 to 6, wherein, prior to draining by the backwashing, the primary washing is performed so that air bubbles can be generated in the primary chamber by the backwashing. Supply the pressurized gas for backwash from the air bleeding means on the side and the secondary side The filtration device, further comprising means.

8. In the back washing method for the filtering device, the compressed gas is caused to flow backward from the secondary side of the filtering device at the time of back washing of the filtering device, thereby generating bubbles in the filtered fluid on the primary side of the filtering device. The gel substance and the Z or highly viscous substance trapped in the filter element of the filtration device are dispersed in the filtration fluid on the primary side of the filtration device, and then the dispersed gel material and / or A method for back washing a filtration device, comprising: discharging a substance having high viscosity together with the filtration fluid on the primary side from the filtration device.